A first attempt to fabricate high reflectivity W/Be and Mo/Be multilayer mirror coatings for near normal incidence and grazing angle applications is reported. Forty layers each of W and Be were laid down alternatively on super polished fused silica substrates by sputter deposition with layer thicknesses of 16 angstroms and 40 angstroms, respectively and a 80 angstroms thick Be capping layer. Soft x-ray reflectivity measurements were carried out using the NRL reflectometer at the Brookhaven National Synchronous Light Source. Measurements at two grazing angles and photon energies yielded the following peak reflectivities: 14.3% (at 14.68 degree(s) and 439 eV) and 7.5% (at 20.2 degree(s) and 307 eV). Model peak calculations taking into account interlay roughness indicate layer roughness of 5.4 angstroms (rms) and a BeO thickness of 70 angstroms in the Be capping layer. In an attempt to reduce interlayer roughness and/or intermixing by reducing the bombardment of high energy Ar neutrals on the growing layers, experiments are underway to replace Ar as the sputter gas with Xe for the W/Be multilayer coatings.

Date Published: 11 November 1994
PDF: 7 pages
Proc. SPIE 2279, Advances in Multilayer and Grazing Incidence X-Ray/EUV/FUV Optics, (11 November 1994); doi: 10.1117/12.193150

Published in SPIE Proceedings Vol. 2279:
Advances in Multilayer and Grazing Incidence X-Ray/EUV/FUV Optics
Richard B. Hoover; Arthur B. C. Walker Jr., Editor(s)